Pete Wentz and Ashlee Simpson at Bravo Supershow 2008 at Arena Nurnberg. Nuremberg, Germany - 03.05.08

The pop couple was rumoured to be planning a ceremony for this Friday (16May08), but now Us Weekly magazine claims Simpson will become Mrs. Wentz on Saturday.

The location, time and all other details are being kept a closely-guarded secret.

A source close to the pair tells the publication, "Proper invites have not been sent out but guests have been given a save-the-date notice."

A rehearsal dinner, for "family and close friends only," will take place on Friday (16May08).

The couple announced its engagement in April (08) and Simpson is rumoured to be pregnant with her fiance's child.

Source: WENN